This invention relates to a mine roof support, and in particular to a mine roof support for use in coal mines.
When mining coal, using the so-called long wall method, a coal winning machine is moved along a coal face, and coal removed from the coal face by such machine is carried by a conveyor from the coal face. When using this method in the mining of a thick seam, coal is left in the top of the coal seam, i.e., the coal winning machine cannot mine the full thickness of the seam. The hydraulic supports used in long wall mining have a definite limit of vertical extension. Even though the coal winning machines can evacuate to greater heights, the usual hydraulic support has an upper limit of ten feet. If the coal seam is thicker than ten feet, a large quantity of coal can be left. The support of the present invention is intended to support the roof of the seam in a direction extending away from the coal face, and to facilitate the controlled, safe recovery of coal from the roof of the seam.